OK, my thoughts are that the salt is slow acting and will take some time to work. Issue with medicating is that the size of tank makes it challenging. Can you get a bottle of Melafix at your local pet or fish shop. It's a natural anti-bacterial that I read is safe for frogs (when dosed correctly). Only thing is, can't find if there are any side effects on a bloated frog. Keeps those pics of frog handy to compare with frog in a couple day's to check for improvement. Good luck!